Parts supply system problem detection support system and method, and program for the same

ABSTRACT

In order to produce high quality final products cheaply using a large-scale production chains, not just the production being performed in the present production unit, but also parts supplies chains must be rational and without waste or overburdening. However, there is presently no means for discovering whether parts supplies chains are irrational, without waste or overburdening, or are rational and without waste or overburdening. 
     A hierarchical tree table of product-parts lists of multi-stages may be displayed with at least one item of parts supply information, this being selected out of production unit of the parts, number of parts, lead time of the parts, cost of the parts, etc. The retrieved parts supply information is displayed in a manner allowing it to be distinguished from other items of parts supply information. The method of retrieval can be set as desired. The entirety of the parts supplies chains is displayed graphically, and the location where the problems exist becomes clear.

TECHNICAL FIELD

The present invention relates to a technique for managing a productionchains. In the production chains, a production activity such as partsproduced in a production unit are used in a subsequent production unitto produce high level parts and a subsequent production activity such asthe high level parts produced in the subsequent production unit are usedin a more subsequent production unit to produce even higher level partsare repeated at multi-stages. The chains of production activities arerepeated in sequence to produce final products at the end. The presentinvention relates to a technique for managing the production chains sothat the final products with high quality can be produced at a low costwithin a short time.

BACKGROUND ART

In producing, for example, a car, coils are produced in a productionunit, the coils are used in a subsequent production unit to producearmatures, the armatures are used in a subsequent production unit toproduce motors, the motors are used in a subsequent production unit toproduce fuel pumps, the fuel pumps are used in a subsequent productionunit to produce fuel pump assemblies, the fuel pump assemblies are usedin a subsequent production unit to produce fuel tank assemblies, and thefuel tank assemblies are used in a subsequent production unit to producecars. A production activity such as parts produced in a formerproduction unit are used in a subsequent production unit to produce highlevel parts is repeated many times or multi-stages in a normalproduction chains.

In the present specification, a production unit is numbered from thehighest side, and a production unit that produces final product istermed the present production unit. In the example given above, thecoils are produced in a sixth production unit, the armatures in a fifthproduction unit, the motors in a fourth production unit, the fuel pumpsin a third production unit, the fuel pump assemblies in a secondproduction unit, and the fuel tank assemblies in a first productionunit. The fuel tank assemblies produced in the first production unit aredelivered to the present production unit, and the final products (thecars) are produced in the present production unit.

The aforementioned ‘first production unit’ could instead be consideredas ‘the present production unit’ in a case that the fuel tank assembliesare produced as final products. In this case, the ‘second productionunit’ described earlier is now the ‘first production unit’ and the‘third production unit’ is now the ‘second production unit’. Anyproduction unit that receives lower parts and produces higher parts byusing lower parts can be deemed to be the ‘present production unit’, andthe production units preceding it may be termed the ‘first productionunit’, ‘second production unit’, ‘third production unit’, etc. Thetechnique of the present invention assists findings of problems byrevealing problems existing but concealed within parts supplies chainsthat supply parts to the present production unit. The technique of thepresent can be applied to any production unit in which lower level partsare used to produce higher level parts.

To produce high quality final products at a low cost within a short timein a production chains, parts supplies chains for the production chainsmust be rational. Waste or overburdening should be excluded from theparts supplies chains for the production chains. For example, in eachproduction unit within the parts supplies chains, the rate of defectiveparts should be low, the number of inventoried parts should be less,production and delivery should take place within a short time, and thenumber of part suppliers should be reduced to an appropriate number.

However, under present circumstances there is no means for learningwhether parts supplies chains are irrational with waste oroverburdening, or are rational without waste or overburdening. JapanesePatent Laid Open Publication 2001-331535 and Japanese Patent Laid OpenPublication H9-267239 set forth a technique for graphically displayingan overall relation of various parts defined by a product—first levelparts list, first level part—second level parts list, second levelpart—third level parts list and so on. The overall relation defined bythe upper level part—lower level parts list at multi-stages isgraphically displayed by using linking information defining hierarchicrelationship. When a higher level part is designated, it is possible toidentify chains of lists of lower level parts at various levels thatconstitute the higher level part.

Even though the lists of the lower level parts at various levels thatconstitute the higher level part is shown graphically, it is notpossible to know from this graphic display whether the parts supplieschains are irrational with waste or overburdening, or are rationalwithout waste or overburdening.

DISCLOSURE OF INVENTION

The present invention teaches a technique for revealing problems (wasteor overburdening) existing and concealed in parts supplies chainsincluding a variety of production units. The present technique furthermakes it possible to take an appropriate countermeasure for solving thefound problem. It thus allows high quality final products to be producedat a low cost within a short period. Further, the present technique mayreveal a part production unit having superior ability that produces highquality parts at a low cost within short period. It thus allowsevaluating the production units reasonably.

In the present invention, a system that reveals problems existing butconcealed in parts supplies chains and assists in finding andrecognizing the in the parts supplies chains has been created.

This system is used to analyze a production chains in which a productionactivity such as parts produced in a former production unit are used ina subsequent production unit to produce high level parts and asubsequent production activity such as the high level parts produced inthe subsequent production unit are used in a more subsequent productionunit to produce even higher level parts are repeated at multi-stages.The final products are produced in the present production unit by usingfinal parts (first level parts) that were produced in final partsproduction unit (first production unit).

The final products referred to here are not limited to final productsfrom the viewpoint of a consumer. As in the example given earlier, thefuel tank assemblies could be also final products when considered fromthe viewpoint of the production unit to produce the fuel tankassemblies. If the final products are the fuel tank assemblies, then theproduction unit of the fuel tank assemblies becomes the presentproduction unit, and the fuel pump assemblies becomes first parts. FIG.1 shows an example of a production chains in which motors are producedin a fourth production unit, fuel pumps are produced in a thirdproduction unit, fuel pump assemblies are produced in a secondproduction unit, the fuel tank assemblies are produced in a firstproduction unit, and cars are produced in a present production unit. Ifone considers the production unit for producing the fuel tanksassemblies to be the present production unit, the second production unitdescribed earlier could now be termed the first production unit, and thethird production unit could now be termed the second production unit.Any production unit in which production is performed by using lowerlevel parts supplied from previous production units can be deemed to bethe present production unit. Consequently the present system can beapplied to any production unit that uses lower level parts supplied fromprevious production units.

This system reveals problems (waste or overburdening) existing andconcealed in parts supplies chains for supplying final parts (firstlevel parts) to the present production unit and assists in grasping theproblems. The system analyzes the parts supplies chains including thefirst production unit and the production units upstream therefrom.

The system of the present teaching comprises the following means:

-   (1) A means for storing a product-parts lists of multi-stages and    parts supplies information The product-parts lists of multi-stages    includes a list of adjoining lower level parts constituting the    final product (a list of first parts), a list of even lower level    parts constituting the lower level parts (a list of second parts    constituting each first part, a list of third parts constituting    each second part, etc.) and linking information of the lists.    Overall lists are formed from chains of lists at multiple stages.    The parts supplies information is related to the first and lower    level parts for the final products and includes at least one item    selected out of the production unit of the part, the number of the    parts required to produce a higher level part, the attribute of the    part, the number of types of the part, the logistics information of    the part, the distance of traveling of the part, the defect rate    during the production of the part, the cost of the part, and the    lead time of the part.

In FIG. 1, an example is shown in which the present production unitproduces the final product ‘A’. A list of first level parts constitutingthe final product ‘A’ is shown to the right of the final product ‘A’, alist of second level parts constituting each first level part is shownto the right of each first level part, a list of third level partsconstituting each second level part is shown to the right of each secondpart, and a list of fourth level parts constituting each third levelpart is shown to the right of each third level part. In the exampleshown in FIG. 1, the first level part B1 is required to produce thefinal product ‘A’, the second level parts C1 and C2 are required toproduce the first level part B1, the third level parts D1 and D2 arerequired to produce the second level part C1, and the fourth level partsE1, E2, E3, and E4 are required to produce the third level part D1.

-   (2) A means for graphically displaying the product-parts relations    stored in the storing means (1) and the parts supplies information    corresponding to each of the parts stored in the storing means (1).-   (3) A means for retrieving, according to prescribed retrieving    criteria, the parts supplies information corresponding to each of    the parts.-   (4) A means for displaying the parts and/or the parts supplies    information corresponding to the parts, these (this) having been    retrieved by the retrieval means, in the graphic display to be    distinguished from the others.

The schematic example of FIG. 1 shows that parts supplies information b1is displayed corresponding to the first part B1. Further, parts suppliesinformation c1 is displayed corresponding to the second level part C1,and parts supplies information c2 is displayed corresponding to thesecond level part C2. The part supplies information b1, c1, and c2 eachcomprises at least one item of the parts supply information of the partsB1, C1, and C2. Specifically, at least one item of information isselected out of the production unit for the part (there may also be aplurality of production units), the number of parts required to producea higher level part, the attribute of the part (distinguishing whetherthe part is, for example, a special purpose part or a general purposepart), the number of types of the part, logistics information of thepart (distinguishing whether the part is, for example, delivered frominventory or directly from a production unit, and whether the part isdelivered via a trading company or is delivered directly from aproduction unit), the distance of traveling of the part, the defect rateduring the production of the part, the cost of the part, and the leadtime of the part. One, or two or more items of information can beselected.

The retrieving criteria can be set in various ways. It is possible toretrieve: parts of which a number of production units is equal to orexceeds a prescribed number, parts of which number is equal to orexceeds a prescribed number to produce a higher level part, parts ofwhich number of types is equal to or exceeds a prescribed number, partshaving prescribed distribution conditions, parts of which distance oftraveling exceeds a prescribed distance, parts of which defect rateexceeds a prescribed rate, parts of which cost is equal to or exceeds aprescribed cost, parts of which lead time is equal to or exceeds aprescribed lead time, etc. The retrieving criteria may be set inadvance, or may be set as required.

As shown schematically in FIG. 1, the entirety of the parts supplieschains can be visualized by graphically displaying product-partsrelations at multi-stages and the parts supplies informationcorresponding to each of the parts. The entirety of the parts supplieschains may be understood visually.

When the graphic display shows the parts and/or the parts supplyinformation corresponding to each of the parts, which have (has) beenretrieved according to the prescribed retrieving criteria, to bedistinguished from the others, problems in the parts supplies chains arerevealed or visualized (for example, if there is a higher level parthaving a large number of adjoining lower level parts, that higher levelpart will be distinguished from the other; if there is a part which havea long lead time, that part will be distinguished from the other; ifthere is a part which has an extremely high price, that expensive partwill be distinguished from the other). The findings or recognition ofproblems that exist but concealed in the parts supplies chains are thuseffectively assisted or supported.

The quantity of information shown schematically in FIG. 1 is extensive,and is not easy to prepare or collect. However, from the presentproduction unit, it is rather easy to collect the part suppliesinformation of the first level part produced in the first productionunit, such as the production unit for the part, the number of partsrequired to produce a higher level part, the attribute of the part thenumber of types of the part, logistics information of the part, thedistance of traveling of the part, the defect rate of the part, the costof the part, and the lead time of the part. However, it is verytroublesome to collect parts supplies information from the secondproduction units, the third units and so on.

To deal with this, it is preferred that a plurality of storing means areconnected by a network into one united storing means: this storing meansstores product-parts lists at multi-stages, and the parts suppliesinformation corresponding to each of the parts included in theproduct-parts lists at multi-stages.

If this is done, each storing means may be managed by each of productionunits. Each storing means may store upper level part-lower level partslist at single stage. Further, each storing means stores the partssupplies information corresponding to each of lower level parts.Moreover, each storing means stores the linking information; thislinking information designates the storing means prepared by lower levelproduction units which supply the lower level parts.

In the case shown in FIG. 1, the storing means 103 of the firstproduction unit stores the data that the second parts constituting thefirst part B1 are C1 and C2. The storing means 105 of the secondproduction unit stores the data that the third parts constituting thesecond part C1 are D1 and D2. Another storing means of the secondproduction unit stores the data that the third part constituting thesecond part C2 is D3. The storing means 107 of the third production unitstores the data that the fourth parts constituting the third part D1 areE1, E2, E3 and E4. Another storing means of the third production unitstores the data that the fourth parts constituting the third part D2 areE5, E6, E7, and E8. Furthermore, the storing means 103 of the firstproduction unit stores the linking information to a storing means 105 ofthe second production unit, which stores the second part C1 as a partthat is produced in the second production unit. The storing means 105 ofthe second production unit stores the linking information to a storingmeans 107 of the third production unit, which stores the third part D1as a part that is produced in the third production unit.

Connecting a plurality of storing means by a network makes it possibleto prepare the huge-scale data base having multi-stages. Each storingmeans may store only single-stage data base. Each data base ofsingle-stage may be prepared within a short time. Connecting theplurality of storing means, each storing means storing single-stage database, makes it possible to prepare the huge-scale data base havingmulti-stages within a short time. The huge-scale data base havingmulti-stages stores product-parts lists at multi-stages and the partssupplies information of each of the parts. The huge-scale data basehaving the extensive quantity of information that constitutes theentirety of the parts supplies information for the large-scaleproduction chains may be prepared within a short time.

Although the retrieving criteria can be set in various ways, it ispreferred to use reference values as the retrieving criteria. Further,it is preferred to add a means for displaying a list of standardcountermeasures. When retrieved items have failed to fulfill thereference values, standard countermeasures that will allow the referencevalues to be satisfied will be indicated in addition to the problem.

For example, when the number of lower level parts constituting a highlevel part has been stored as a portion of parts supplies information,it is possible to retrieve the high level part of which number of lowerlevel parts is equal to or greater than the prescribed number. Thus onecan extract the high level part requiring a large number of lower levelparts. If this is done, the standard countermeasures are displayed toreduce the number of required low level parts, such as integrating thelow level parts, redesigning of the high level part. That is, thepresence of a problem and its countermeasures are displayed. Problems inthe parts supplies chains should thus be improved speedily.

It is preferred that each of the lower level parts is displayedgraphically on product-parts lists of multi-stages with its productionunit.

If this is done, it becomes apparent whether parts supplies chains foran identical part are overlapping or not, or whether a particularproduction unit has many problems with the parts supply. It becomesconsequently easy to take the necessary countermeasures. Alternatively,outstanding or superior production units become apparent and superiorproduction units are given opportunities of their outstanding abilitiesbeing evaluated accurately. It also becomes easy for a production unitthat needs a lower level parts supplier to find a superior productionunit having outstanding ability to supply the lower level parts. Itbecomes easy to establish parts supplies chains that supply parts insequence at a low cost and within a short time.

It is preferred that each of the lower level parts is displayedgraphically on the product-parts lists of multi-stages with the numberof parts required to produce a higher level part.

If this is done, a part that requires a large number of the lower levelparts can be identified, and it is easy to detect the part of whichlower level parts require integration or to be assembled into one part.

It is preferred that each of the constituting parts is displayedgraphically on the product-parts lists of multi-stages with itsattribute.

Here, the term ‘attribute of the part’ refers to whether the part is aspecial purpose part used only in one type of final products, a commonpart used commonly in various types of final products, or a generalpurpose parts that circulate normally in the market.

Cost and lead time can be reduced by using common parts and generalpurpose parts instead of special purpose parts. The above display allowsthe current situation to be understood easily from this viewpoint.

It is preferred that each of the constituting parts is displayedgraphically on the product-parts lists of multi-stages with its numberof types.

If this is done, parts having a large number of types can be identified,and it is easy to detect parts which need be redesigned to be replacedby common parts or parts in series.

It is preferred that each of the parts is displayed graphically on theproduct-parts lists of multi-stages with its logistics information fromthe production unit of the part to a subsequent production unit.

Here, ‘logistics information’ refers to information indicating whetherthe part is delivered from inventory, for example, or delivered via atrading company, or others. Distribution cost can be included asrequired.

When the logistics information is displayed, waste or overburdeningrelating to delivery conditions is made visible, and problems are thusdetected.

It is preferred that each of the parts is displayed graphically on theproduct-parts lists of multi-stages with its distance of traveling fromthe production unit of the part to a subsequent production unit.

When the distance of traveling required for delivery of the part isdisplayed, problems relating to the geographical location of the partproduction units are made visible, and problems are thus detected.

It is preferred that each of the parts is displayed graphically on theproduct-parts lists of multi-stages with the defect rate during theproduction of the parts.

When the probability (percentage) of defective parts during theproduction is displayed, production units which have problems aredetected, and countermeasures to improve quality therein can be taken.

It is preferred that each of the parts is displayed graphically on theproduct-parts lists of multi-stages with its cost.

If this is done, parts of which cost should be reduced become apparent,and the information to analyze the reason of the high cost is displayed.It thus becomes easy to take effective countermeasures to reduce thecost.

It is preferred that each of the parts is displayed graphically on theproduct-parts lists of multi-stages with its lead time.

If this is done, parts of which lead times need to be shortened becomeapparent and the information to analyze the causes of the long lead timeis displayed. It thus becomes easy to take effective countermeasures toshorten the lead time.

It is further preferred that, for each of the parts, each of lead timesdivided into each step from ordering until delivery are displayed.

The total lead time can be divided into, for example, the time fromordering until the beginning of production, the time from the beginningof production to the completion of production, the inventory time inwhich the parts are stored from the completion of production untilshipping, and transport time from shipping until delivery. If each oflead times of each of steps is displayed separately, it becomes easy totake effective countermeasures to shorten the total lead time. Further,the separation of lead times into multi-steps is not limited to theexample described above.

It is further preferred that the total lead time of each of the parts isdisplayed with each of lead times of each of production units from thelowest level part to adjoining low level part, these constituting onepart.

If, for example, it is displayed that the lead time is 0.5 day for thefourth part, is 0.5 day for the third part, is 0.5 day for the secondpart, and thus is 1.5 days for the first part, the total of the leadtime becomes apparent.

It is preferred that for each of the low level parts graphically shownon the product-parts lists of multi-stages, at least one item selectedout of the number of parts required to produce a higher level part, theattributes of the part, and the number of types of part, as well as thecost of the part and the lead time of the part are displayed in a mannerof comparison.

If this is done, technical information relating to the partconfiguration, cost information, and lead time information are displayedin a manner of comparison. Consequently, it becomes possible tocomprehensively grasp the parts supplies chains from the aspects oftechnique, production, and distribution, and it becomes easy to takecomprehensive countermeasures.

Moreover, required items other than the aforementioned items can also bedisplayed.

In the present invention, a method has been created that revealsproblems existing but concealed in parts supplies chains and thus makesit easy to find these problems. The following steps are executed in themethod of the present teaching:

-   (1) A step for each of production units to prepare a database. Each    of production units prepares a list of adjoining lower level parts    required for producing the part in the production unit. That is, the    each production unit prepares product-parts list at single-stage.    The product corresponds to the part produced in the production unit.    Further, each production unit prepares parts supplies information    corresponding to each of the adjoining lower level parts, the parts    supplies information being at least one item selected out of the    production unit of the part, the number of parts required to produce    a higher level part, the attribute of the part, the number of types    of part, the logistics information of the part, the distance of    traveling of the part, the defect rate during the production of the    part, the cost of the part, and the lead time of the part.-   (2) A step for each of production units to prepare linking    information. The linking information connects the data base prepared    by the production unit to lower level databases prepared by lower    level production units. The connected lower level database stores    product-parts list, in which the ‘product’ is one of the adjoining    lower level parts within the higher level database prepared the    higher level production unit.-   (3) A step of graphically displaying product-parts lists of    multi-stages. The product-parts lists of multi-stages includes final    product-first parts list, first part-second parts list and so on.    Product-parts lists of multi-stages are assembled from each    product-parts list of single-stage and linking information prepared    by each of production units. Parts supplies information    corresponding to each of the parts is also displayed.

In the present method, each of production units prepares product-partslist of a single-stage. The product in the list corresponds to the partproduced in the production unit. Parts in the list correspond toadjoining lower level parts required for producing the product in thelist. Further, each of production units prepares at least one item ofparts supplies information corresponding to each of the adjoining lowerlevel parts. At this juncture, it is sufficient to merely investigatethe adjoining lower level part production units and parts, and theinvestigation needs not be followed back further. Consequently, areliable database is completed relatively easily.

Each of production units prepares liking information for connecting itsdatabase to lower level databases prepared by lower level productionunits. The connected lower level database stores product-parts list, inwhich the ‘product’ is one of the adjoining lower level parts within theupper level database prepared the upper level production unit.Consequently, these databases, which are prepared independently, formone united large-scale database indicating the product-parts lists ofmulti-stages. The product-parts lists of multi-stages include finalproduct—first parts list, first part—second parts list and so on, andthe lists are connected with hierarchy. The united large-scale databasealso includes parts supplies information corresponding to each of theparts included in the product-parts lists of multi-stages.

In the case of FIG. 1, the database 103 of the first production unitstores the data that the second parts that constitute the first part B1are C1 and C2. The database 105 of the second production unit stores thedata that the third parts that constitute the second part C1 are D1 andD2. The database 107 of the third production unit stores the data thatthe fourth parts that constitute the third part D1 are E1, E2, E3, andE4. Furthermore, the database 103 of the first production unit storesthe linking information to the database 105 of the second productionunit, this storing the second part C1 as a part that is produced. Thedatabase 105 of the second production unit stores the linkinginformation to the database 107 of the third production unit, thisstoring the third part D1 as a part that is produced.

The following program is useful to complete the aforementioned database,in which the plurality of independent databases is linked to constructone united large-scale database The program of the present inventionoperates a computer that is managed by each of production units so as toexecute the following steps:

-   (1) A step for assisting an operator to input a product-parts list    into the computer. The product in the list corresponds to the part    produced in the production unit. Parts in the list correspond to    adjoining lower level parts required for producing the product in    the list.-   (2) A step for assisting an operator to input parts supplies    information corresponding to each of the lower level parts in the    list to the computer. The parts supplies information is at least one    item selected out of: the production unit of the part, the number of    parts required, the attribute of the part, the number of types of    part, the logistics information of the part, the distance of    traveling of the par, the defect rate during the production of the    parts, the cost of the part, and the lead time of the part.-   (3) A step for assisting an operator to input linking information to    the computer. The linking information designates databases prepared    by lower level production units for producing adjoining lower level    parts.

If this program is used in each of production units and each database isconstructed in accordance with the program, it is possible, merely byinputting data concerning the adjoining lower level parts, to completeone united database which stores the entirety of large-scale partssupplies chains, these chains are linked at multiple stages. Moreover,the database does not necessarily need to be completed without any gaps.The database still functions when a portion of the data has not beenobtained.

The method of the present invention can be considered as a method forrevealing advantages and disadvantages concealed within the partssupplies chains that are formed from a sequence of production units fromthe lowest level parts production units up to final parts productionunit. In this method, the following steps are executed:

-   (1) At each of production units in the parts supplies chains;-   (1a) a step of preparing product-parts list. The product in the list    corresponds to the part produced in the production unit. Parts in    the list correspond to adjoining lower level parts required for    producing the product in the list.-   (1b) a step of preparing parts supplies information. The parts    supplies information is at least one item selected out of: number of    lower level parts required to produce the upper level part,    attribute of the lower level part, and number of types of the lower    level part.-   (1c) a step of preparing another parts supplies information. The    parts supplies information is at least one item selected out of:    lead time and cost of the adjoining lower level part required, and-   (2) a step of preparing linking information to a database that has    been prepared by the production unit producing the adjoining lower    level parts.

Here, the method is characterized in that each database has a commonformat.

There are various production units for various parts. There areproduction units that chiefly utilize chemical reactions, productionunits focusing on machine work, production units focusing on assembly,production units focusing on heat treatment or others. Each of everyproduction units pays extreme efforts to overcome waste or overburdeningin each production unit. For example, it collects and analyzes numericalinformation relating to productivity. Since the production units havevarying characters, every production unit is quantized to suit itscircumstances. For example, in production units focusing on chemicalreactions, productivity is evaluated by the lot units that react at onetime. However, when the entirety of the parts supplies chains isanalyzed, the data cannot be synthesized due to the variety ofproduction units.

In the present invention it has been ascertained that, even in variousproduction units with differing conditions, it is possible to analyzecost, lead time and others by part basis on a hierarchical product-partslists of multi-stages, and it is possible to utilize a common format.Further, it has been ascertained that, by utilizing the common format,it is possible to obtain one united database describing the entirety ofthe parts supplies chains.

A hitherto unobtainable database describing the entirety of the partssupplies chains is obtained by means of the present method. Analysis ofthe database reveals advantages and disadvantages within the partssupplies chains.

The present invention can be readily understood by reading thedescription of embodiment described below, with reference to thefigures.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a schematic figure of a hierarchical tree structures ofunited product-parts lists of multi-stages.

FIG. 2A shows an example block diagram of a system for revealingproblems and assisting findings of the problems existing and concealedin parts supplies chains.

FIG. 2B shows an example block diagram of a system for revealingproblems and assisting findings of the problems existing and concealedin parts supplies chains.

FIG. 2C shows an example block diagram of a system for revealingproblems and assisting findings of the problems existing and concealedin parts supplies chains.

FIG. 3 shows a flowchart showing sequences of steps for preparing andusing parts supplies chains database.

FIG. 4 shows a sample of a display on a user interface indicatingproduct-parts lists of multi-stages stored in the parts supplies chainsdatabase, reference values, and lists of countermeasures.

FIG. 5 shows a sample of a display on a user interface in which theproduct-parts lists of multi-stages stored in the parts supplies chainsdatabase is graphically displayed as a hierarchical tree structures, andeach part is shown as an icon.

FIG. 6 shows a sample of a display in which parts supply information,reference values, and list of standard countermeasures for each of theparts are shown in one block.

FIG. 7 shows a sample of a display in which parts supply information isgraphically displayed on a map at a location where a production unit islocated.

FIG. 8 shows a sample of a display in which parts supply informationbefore and after the standard countermeasure is taken.

BEST MODE FOR CARRYING OUT THE INVENTION

Next, an example of an embodiment of the present invention will bedescribed. FIGS. 2A, 2B, and 2C show example of a system for revealingproblems and assisting human beings to find and recognize the problemsexisting and concealed in parts supplies chains.

As shown in FIGS. 2A, 2B, and 2C, a computer 203 for analyzing partssupplies chains, a computer 207 managed by a present production unit, acomputer 230 managed by a first production unit, and a computer 240managed by a second production unit, are each connected with a network201. Not all the computers are shown. There is a plurality of firstproduction units, and a plurality of computers is used therefore. Thereis also a plurality of second production units, and a plurality ofcomputers is used therefore. Computers used for production units atlower levels than the third production unit are also connected with thenetwork 201. An input-output device is connected with each computer.

As shown in FIG. 2A, the computer 203 for analyzing parts supplieschains comprises: a retrieval program for retrieving parts suppliesinformation stored with respect to each part of product-parts lists ofmulti-stages; a database that stores reference values and lists ofstandard countermeasures for enabling those reference values; and adatabase that stores the location and name of each of the productionunits. It further comprises a program for preparing and outputting datatables concerning the parts supplies chains (to be described).

As shown in FIG. 2A, computer 207 of the present production unitcontains: a program for preparing a parts supplies chains database, andthe parts supplies chains database. The parts supplies chains databasestores a product-parts lists of single-stage that describes relationsbetween a final product and parts (first level parts) constituting thefinal product, and the parts supply information relating to each of thefirst level parts.

As shown in FIGS. 2B and 2C, the computers 230 and 240 managed by thelower production unit respectively stores a product-parts lists ofsingle-stage that describes relations between a product and partsconstituting the product, and the parts supply information relating toeach of the lower level parts. The one of lower parts in the computer207 is the product in the computer 230, and the one of lower parts inthe computer 230 is the product in the computer 240.

As shown in FIGS. 2A, 2B, and 2C, the computer 207 of the presentproduction unit, the computer 230 of the first production unit and thecomputer 240 of the second production unit, and others are linkedtogether via the network 201 to form one united large-scale database.

FIG. 3 shows an entirety of a procedure, from a step in which a partssupplies chains database is organized (to be described) until problemsare revealed.

As shown in step S301 of FIG. 3, each of production units prepares eachparts supplies information and linking information to lower leveldatabase by using the program for preparing the parts supplies chainsdatabase and corresponding computers 207, 230 and 240.

Specifically, as reference 207 of FIG. 2A, 230 of FIG. 2B, and 240 ofFIG. 2C shows, each of production units prepares product-parts list. Theproduct in the list means the product produced in the production unit(for the present production unit, the product means the final product).The parts in the list mean the adjoining lower level parts thatconstitute the product in the list. Using the program allows these itemsof information to be set up as a formalized standard format.

FIGS. 2A, 2B, and 2C show an example of one database that has beenprepared. Each database is prepared by the computers 207, 230 and 240and others managed by each production unit respectively.

As shown in FIG. 2A, the final products produced in the presentproduction unit is shown at a product section 209 of the database storedin the computer 207 managed by the present production unit. The producthas been represented by the term ‘A’, but may be represented by aproduct number or the like. Further, the parts produced in eachproduction unit following a first production unit are represented asproducts in the database.

The adjoining lower level parts constituting the product shown in theproduct section 209 are shown in parts section 211. In FIG. 2A, theparts B1 and B2 that constitute the final product A are represented. Asshown in FIG. 2B, the computer 230 of the first production unit storesthe data that the first part B1 is produced using second parts C1 andC2, and as shown in FIG. 2C, the computer 240 of the second productionunit stores the data that the second part C1 is produced using thirdparts D1 and D2.

Production units for producing the adjoining lower level parts aredisplayed in a production unit section 213. In FIG. 2A, the location andname of the production units for producing the lower level parts areshown. Specifically, the example shows that the lower level parts B1 areproduced both in Okazaki 2Aa and Okazaki 3Bb. Okazaki 2Aa means aproduction unit ‘a’ of line ‘A’ of factory ‘2’ in Okazaki’; and Okazaki3Bb means a production unit ‘b’ of line ‘B’ of factory ‘3’ in Okazaki’.

The number of parts is displayed as a figure in a number of partssection 215. ‘Number of parts’ refers to the total number of adjoininglower level parts used for manufacturing one product (in the productionunits below the first production unit, product corresponds to part).

The number of types and attribute of the part are shown in a number oftypes of part, attribute of the part section 217. The ‘number of types’displays, by means of a number, how many version of the same part isbeing manufactured. Furthermore, ‘attribute of the part’ refers to aclassification of the part into special purpose part, common part, andgeneral purpose part. Since there are two versions of the part B1, thenumber ‘2’ is shown in FIG. 2A Further, since B1 is a special purposepart, the number ‘2’ is shown in the ‘special purpose part’ column ofthe attribute of the part.

Information concerning the logistics of the part from the productionunit to the upper production unit is stored in a logistics informationsection 219. In this section, ‘inventory’ is displayed if the part isdelivered from inventory, ‘trading company’ is displayed if the part isdelivered via a trading company, and ‘payment required’ is displayed ifpayment is required for the services of delivering the part.

In a distance of traveling section 221, the distance over which partmoves from its production unit to the subsequent production unit isindicated. The distance is represented by a bar that extends in ahorizontal direction that corresponds with distance. For the first partB1, for example, a distance from the ‘Production unit of line A offactory 2 in Okazaki’ to the present production unit is displayed.

In a defect-rate section 223, the probability of defective parts beingproduced is represented by a bar that extends in a horizontal direction.The length of the bar corresponds to a percentage of defective parts.

In a cost section 225, the cost of each part is represented by a barthat extends in a horizontal direction. The length of the barcorresponds to the cost of each part.

In a lead time section 227, the lead time required from ordering untildelivery of the part is represented by a bar that extends in ahorizontal direction. The length of the bar corresponds to the length ofthe lead time. The lead time can be displayed divided into lead timesfor each step from ordering until delivery. This consists of: productionlead time, referring to the time from receiving orders until thecompletion of production in the lower level production unit; inventorylead time, referring to the time in which the completed part is storeduntil it is shipped; and delivery lead time, referring to the time takenfor transporting the part from the lower level production unit to thehigher level production unit. Alternatively, these lead times can beshown in total. In FIG. 2A, the production lead time, the inventory leadtime, and the delivery lead time are each displayed, and their total isalso displayed.

The computer 230 of FIG. 2B managed by the first production unit alsoprepares a database having the same configuration, and the computer 240of FIG. 2C managed by the second production unit also prepares adatabase having the same configuration. The part stored in the computer207 of FIG. 2A managed by the present production unit is stored as aproduct in the computer 230 for the first production unit of FIG. 2B.The part stored in the computer 230 of FIG. 2B managed by the firstproduction unit is stored as a product in the computer 240 for thesecond production unit of FIG. 2C.

Databases in the computers 207, 230 and 240 are independently prepared.The linking information to the lower level database is utilized toconnect databases from higher level production unit to lower levelproduction unit. Specifically, as shown by 229 in FIGS. 2A and 2B, 233in FIGS. 2B and 2C, the computer for the lower production unit thatproduces the adjoining lower level parts becomes a link destination.FIGS. 2A, 2B, and 2C show the following: the linking information 229links the data in the computer 207 (this computer 207 is provided withthe present production unit) concerning the first part B1 that isdelivered from Okazaki 2Aa to the present production unit with thedatabase having the product of B1 in the computer 230 (this computer 230is provided with the production unit of Okazaki 2Aa). Further, thelinking information 233 links the data in the computer 230 (thiscomputer 230 is provided with the first production unit) concerning thesecond part C1 that is delivered from Hamamatsu 1Ba to Okazaki 2Aa withthe database having the product of C1 in the computer 240 (this computer240 is provided with the production unit of Hamamatsu 1Ba).

FIGS. 2A, 2B, and 2C show an example of the database concerning theparts supplies chains that constitute the final product ‘A’. Thedatabase concerning the parts supplies chains of the first parts thatconstitute the final product ‘A’ is within the data base prepared by thepresent production unit for producing the final product. The linkinginformation to the database concerning the parts supplies chains of thesecond parts that constitute the firs part is also within the data baseprepared by the present production unit for producing the final product.The database concerning the parts supplies chains of the second partsthat constitute the first parts is within the data base prepared by thefirst production unit for producing the first part. The linkinginformation to the database concerning the parts supplies chains of thethird parts that constitute the second part is also within the data baseprepared by the first production unit for producing the first part. Thedatabase concerning the parts supplies chains of the third parts thatconstitute the second parts is within the data base prepared by thesecond production unit for producing the second part. The linkinginformation to the database concerning the parts supplies chains of thefourth parts that constitute the third part is also within the data baseprepared by the second production unit for producing the second part.

The linked database is edited into one united large-scale database thatcovers multi-stages database from the lowest level to the highest level.This editing is done by the computer 203 for analyzing the partssupplies chains. The united large-scale database includes product-partslists of multi-stages in which product-parts (product)-parts(product)-parts (product) information is stored. The linking informationis used to assemble product-parts list of single-stage into multi-stagesor chains. Corresponding to each of the parts in the product-parts listsof multi-stages, the part supplies information of the part is stored.The parts supplies chains database of multi-stages is thus completed(FIG. 3, S301).

In this manner, by preparing adjoining lower information at eachproduction unit (this information being comparatively easilyresearched), one united large-scale database that describes the entiretyof the parts supplies chains of a large-scale production chains can beprepared. The united large-scale database contains an extensive quantityof information.

The completed parts supplies chains database, which is edited by thecomputer 203 for analyzing the parts supplies chains, is shown on theoutput device of the computer 203 or on the output device of the presentproduction unit computer 207 (FIG. 3, S303).

The computer 203 executes retrieval processes on the edited partssupplies chains database. FIG. 3 shows the sequence of display procedureof the result. First, target reference values are determined for eachitem of parts supplies information. Further a list of standardcountermeasures is prepared for each item of parts supplies information.The standard countermeasures are expected to improve the problems thatthese reference values are not fulfilled. Target reference values andstandard countermeasures are then put into the database of the computer203 for analyzing the parts supplies chains (S305). Next, the parts andthe production units that do not fulfill the reference values areretrieved (S307). The name and/or the parts supplies information of theparts that do not fulfill the reference values (which have been obtainedfrom the retrieved results) are highlighted in an output device 205 ofthe computer 203. Consequently, they can be recognized at a glance.Furthermore, the lists of standard countermeasures are shown togetherwith them. In this manner, problems in the part supplies chains andtheir countermeasures are shown to the final product production unit.Problems in the parts supplies chains should consequently be rapidlyimproved.

FIG. 4 is an example displaying the reference values and standardcountermeasures in a parts supplies chains database edited by using thelinking information. In this case, parts section is schematically shownwith a multiple tree structure. Specifically, the columns for B1 (thetop lines) reach to the left edge of the parts region. This shows thatB1 is the adjoining lower level part of the final product ‘A’. Thisfurther shows that B1 is produced in two production units: ‘Okazaki 2Aa’and ‘Okazaki 3Bb’. The columns for C1, which are located below thecolumns for B1, begin one step further to the right than the columns forB1. This shows that C1 is the adjoining lower level part to B1, andshows that C1 is produced in two production units. In the same way, thecolumns for D1 begin one step further to the right than the columns forC1 and show that D1 is the adjoining lower level part to C1 and that D1is produced in two production units.

Reference values 401 may be shown as concrete number enclosed within acell. The reference number may also be designated by a vertical straightline or the like. For example, as shown by 401, the number of parts hasthe reference value ‘2’. Further, the distance of traveling has thereference value ‘200’, and this is also designated by a verticalstraight line.

Moreover, a standard countermeasure 403 for each part is displayed whenitems of parts supplies information do not fulfill the reference values.For example, the same part B1 is produced in two production units andthis duplication is indicated by the number ‘2’ in the production unitssection. The reference value for the duplication is ‘1’. The standardcountermeasure to be required for this case, ‘aggregation’ is shown. Inthis case, the letter ‘A’ represents aggregation. Similarly, the numberof parts is indicated by the number ‘4’ and this exceeds its referencevalue ‘2’. The standard countermeasure to be required for this case,‘integrate’ (represented by the letter ‘B’) is shown. The number oftypes and attribute of the part, ‘special purpose part 2’ is shown. Thisexceeds its reference value, which is ‘common part 1’. Consequently, thestandard countermeasure to be required for this case, ‘use common partor general purpose part’ (the letter ‘C’) is shown. Standardcountermeasures for fulfilling the reference values are shown in thesame way for each further item which does not fulfill the referencevalues. In the case where the reference values cannot be fulfilled forthe logistics information, ‘direct delivery’ (‘D’) is shown; for thedistance of traveling, ‘shorten distance’ (‘E’) is shown; for the defectrate, ‘improve quality’ (‘F’) is shown; for the cost, ‘reduce number ofparts or use general purpose parts’ (‘G’) is shown; for the lead time,‘shorten traveling distance’ (‘H’) is shown, etc. Only a portion of thestandard countermeasures are shown in the figure, whereas a plurality ofstandard countermeasures has been stored.

Most parts fulfill the reference values when the part supplies chainshave been well set up, while the items that do not fulfill the referencevalues are shown clearly in the graphic representation.

As shown in S311 and S313 in FIG. 3, one can modify in various ways thedisplay of the reference values and the standard countermeasures in agraphic display of the parts supplies chains data.

The display listed in S313 in FIG. 3 is shown in FIGS. 5 and 6. In this,the parts and the parts supply information are graphically representedwith a hierarchical tree structure.

In FIG. 5, the product-parts lists of multi-stage stored in the partssupplies chains database is displayed with a hierarchical treestructure, each part is shown as an icon and is displayed on a userinterface. The section 501 is not shown on the actual user interface,but is mentioned here for convenience so as to aid understanding of theconnection between each part and its production unit. For example, ifone clicks on the icon 503 for part B1, the parts supply information,the reference values, and the standard countermeasures for the part B1are shown in one block.

FIG. 6 shows an example displayed in one block. Box 601 explains themeaning of the display in the box 603. As shown in the box 601, the leadtime is displayed below the arrow at the left side of the box. Thisarrow indicates the direction from the current production unit to theadjoining higher level production unit. In the box 603, the number ‘0.5’below the arrow shows the number of days. ‘Name of part’ in the box 601refers to the name of the part: this is displayed as ‘B1’ in the box603. Similarly, ‘location and name of production unit’ in the box 601:this is displayed as ‘Okazaki 2Aa’ in the box 603, meaning ‘productionunit a of line A of factory 2 in Okazaki’, the production unit for theparts B1. ‘Number of parts’ in the box 601: this is displayed as thenumber ‘4’ in the box 603, showing that one higher level part isproduced using four parts B1. Moreover, ‘Number of types of part’ in thebox 601: this is displayed as ‘special purpose, 2 types’ in the box 603,meaning that the parts B1 are special purpose parts, and exist in twotypes. ‘Logistics information’ in the box 601: this is displayed as‘inventory’ in the box 603, meaning that the parts B1 are delivered frominventory. ‘Distance of traveling’ in the box 601: this is displayed as‘50 km’ in the box 603, showing the distance from the production unit ofOkazaki 2Aa to the adjoining higher level production unit. ‘Defect rate’on one line below in the box 601: this is displayed as ‘11%’ in the box603, showing the probability of defective parts being produced duringthe manufacture of the parts B1. ‘Cost’ on the bottom line in the box601: this is displayed as ‘1,050 yen’ in the box 603, showing the priceof the part B1. Further, ‘cumulative L/T’ in the box 601 refers to thecumulative lead time from the lowest lower level production unit to theadjoining lower level production unit, and is displayed as ‘10 days’ inthe box 603.

The numbers in the box 603 which are highlighted by being circled areitems which do not fulfill the reference values. Moreover, the standardcountermeasures (represented by letters of the alphabet) for each itemof parts supply information are displayed in the box 603 in the columnscorresponding to the countermeasures columns of the box 601.

All information is thus displayed in one block for each of the parts. Asa result, it is clear which items are problematic.

FIG. 7 shows another example of display listed in S313 in FIG. 3. Here,the parts supply information is graphically represented on a mapindicating a location where the production units are located.

FIG. 7 illustrates the following example. The final products areproduced at the present production unit. The first parts B1 are producedat Okazaki 2Aa of the first production unit. The second parts C1 areproduced at Hamamatsu 1Ba of the second production unit. The third partsD1 (these parts will be delivered to Hamamatsu 1Ba) are produced at aplace 707 of the third production unit. The fourth parts D1 (these partswill be delivered to the place 707) are produced at a place 711 of thefourth production unit. In this case, the location of the presentproduction unit for producing the final product is represented as ‘0’ onthe map (meaning that the present production unit is located at a placeindicted by 701). Similarly, the location of Okazaki 2Aa is representedas ‘1’ on the map (meaning that the first production unit is located ata place indicted by 703). The location of Hamamatsu 1Ba is representedas ‘2’ on the map (meaning that the second production unit is located ata place indicted by 703). The location of the third production unit isrepresented as ‘3’ on the map (meaning that the third production unit islocated at a place indicted by 707). The location of fourth productionunit is represented as ‘4’ on the map (meaning that the fourthproduction unit is located at a place indicted by 711). Further, astraight line connects adjoining higher level and lower level productionunits.

Using this display, the location of each of production units is visuallydefined, as is the linear distance (shown by the straight lines) betweenthe adjoining higher level and lower level production units.

If the traveling distance between the adjoining lower level and higherlevel production units exceeds the reference values, these section ofthe straight lines can be highlighted. For example, in FIG. 7, thelinear distance between the fourth production unit 711 and the thirdproduction unit 707 is highlighted by a thick line (709). Furthermore,clicking on the display of each location 701, 703, 705, 707, and 711gives a detailed display of the parts supply information for the partproduced in each production unit: the display shows whether thereference values are fulfilled or not, and the standard countermeasuresfor the items that the reference value is not fulfilled. For example, ifone clicks on the first production unit 1 (703), the detailed displayshown by 713 is given.

FIG. 8 shows another example displayed in S313 in FIG. 3. This is anexample showing product-parts lists of multi-stages in a form ofhierarchical tree structure. The hierarchical tree structure graphicallyrepresented in 801 of FIG. 8 (this has already been shown in FIG. 5)shows a portion of the parts-supplies chains that constitute the finalproduct A The parts B1, C1, D1, D2, E1, E2, E3, and E4 are graphicallyshown here. The hierarchical tree structure in 801 represents the partssupplies chains before appropriate countermeasures are taken. Thehierarchical tree structure in 802 represents the parts supplies chainsafter appropriate countermeasures are taken for parts in which thereference values had not been fulfilled. In these results, the parts D2,E2, and E3 have been eliminated. In addition, the lower level productionunits have been reduced to extend no further than the fourth productionunit.

The applied countermeasures will now be described. Taking D2 as anexample, the reference values have not been fulfilled in a partattribute section. The standard countermeasure ‘C’ is listed, meaning‘use common parts’. As a result, D2 is changed into a common part withD1 and is integrated with D1. D2 is thus eliminated. In the case of E2and E3, it was ascertained from information of the part production unitsthat these were produced in the same factory where E1 was produced, butwere produced on different lines. As a result, E2 and E3 were installedin E1 in that factory, and E2 and E3 were thus eliminated. In thismanner, the number of parts is reduced, and the number of chains ofproduction units from the present production unit to the lowest levelproduction unit is reduced. This allows the lead time to be shortenedand the cost of the products to be reduced.

If one compares 801 with 802, thus comparing the state before and afterthe standard countermeasures were applied, one can see at a glance thatthe number of parts has been reduced, and hence clearly grasp the effectof applying the countermeasures.

Further, if one clicks on the icon for each part in 802 of FIG. 8, theparts supply information, the reference values, and the standardcountermeasures for each of the parts will also be displayed in oneblock as with the box 603 of FIG. 6. Consequently, if one clicks on theicon for the same part in 801 (before the countermeasures have beenapplied), one can compare, and learn how each item of the parts supplyinformation has been optimized.

In addition, it is possible to retrieval various production units fromthe parts supplies chains databases by setting various retrievingcriteria. If retrieving criteria are input in S315 of FIG. 3, retrievalprocess is performed (S317), and the retrieved results are displayed(S319). If for example, the reference values are equal to the retrievingcriteria, performing a retrieval process reveals which parts do notfulfill the reference values, as well as related items, and problemsbecome clear immediately.

Using the present invention makes it possible to grasp, from the side ofthe production unit of the final product, the entirety of the productionchains and parts supplies chains: whether there are problems in lowerlevel parts or lower level production units, which parts or productionunits have the problems, and what countermeasures can be taken to dealwith these problems. Further, by applying the countermeasures, followingresults will be achieved: the amount of lower level parts held ininventory of higher level production unit is kept to a minimum, highquality final products can be produced at a low cost and within a shorttime, and an efficient production and parts supply chains are attained.

The embodiment described above merely illustrates some possibilities ofthe invention and does not restrict the claims thereof A person skilledin the art can embody the present invention in various aspects withinthe art set forth in the claims.

1. A system for assisting findings of problems by revealing the problems existing and concealed in parts supplies chains, wherein parts produced in a production unit are supplied to and used in a subsequent production unit to produce higher level parts, the higher level parts produced in the subsequent production unit are supplied to and used in a further subsequent production unit to produce even higher level parts, and the sequences are repeatedly executed at multiple steps until final parts are produced in a final part production unit and the final parts are supplied to a final product production unit for producing final products, the system comprising: a means for storing product-parts lists of multi-stages and parts supplies information; wherein the product-parts lists of multi-stages comprises a final product and a list of adjoining lower level parts constituting the final product (a list of first parts), and the lower level part and a list of even lower level parts constituting the lower level parts (a list of second parts constituting the first part, a list of third parts constituting the second part, etc.), wherein the product-parts lists of multi-stages includes linking information for connecting lists in sequences at multi-stages, and wherein the parts supplies information corresponds to each of the lower level parts included in the product-parts lists of multi-stages, the parts supplies information including at least one item selected out of the traveling distance of the part, the defect rate during the production of the part, the cost of the part, and the lead time of the part, and a means for storing reference vales concerning to parts supplies information, a means for graphically displaying the product-parts lists of multi-stages and the parts supplies information corresponding to each of the parts, wherein the product-parts list includes a production unit of the lower level part listed in the list for each lower level part, and the product-parts list is stored for each production unit wherein the graphic display displays the parts supplies chains and parts and parts supplies information, and wherein the parts supply information are displayed in a different mode depending on whether the reference values have been fulfilled or have not been fulfilled.
 2. A system for assisting findings of problems by revealing the problems existing and concealed in parts supplies chains, wherein parts produced in a production unit are supplied to and used in a subsequent production unit to produce higher level parts, the higher level parts produced in the subsequent production unit are supplied to and used in a further subsequent production unit to produce even higher level parts, and the sequences are repeatedly executed at multiple steps until final parts are produced in a final part production unit and the final parts are supplied to a final product production unit for producing final products, the system comprising: a means for storing product-parts lists of multi-stages and parts supplies information; wherein the product-parts lists of multi-stages comprises a final product and a list of adjoining lower level parts constituting the final product (a list of first parts), and the lower level part and a list of even lower level parts constituting the lower level parts (a list of second parts constituting the first part, a list of third parts constituting the second part, etc.), wherein the product-parts lists of multi-stages includes linking information for connecting lists in sequences at multi-stages, and wherein the parts supplies information corresponds to each of the lower level parts included in the product-parts lists of multi-stages, the parts supplies information being at least one item selected out of the traveling distance of the part, the defect rate during the production of the part, the cost of the part, and the lead time of the part, and a means for retrieving parts supplies information stored in connection with each part in accordance with retrieving criteria, a means for graphically displaying the product-parts list of multi-stages and the parts supplies information corresponding to each of the parts, wherein the product-parts list includes a production unit of the lower level part listed in the list for each lower level part and the product-parts list is stored for each production unit wherein the graphic display displays the parts supplies chains and parts supplies information, and wherein the part and parts supply information retrieved by the retrieving means are displayed in a different mode than the other.
 3. A system as set forth in claim 2, further comprising: a means for storing reference values concerning each of the items of parts supplies information, and the aforementioned retrieval means retrieves the parts supply information according to the reference values as the retrieving criteria, and a means for displaying a list of standard countermeasures for achieving reference values, with respect to the parts supplies information failing to fulfill the reference values and retrieved.
 4. A system as set forth in claim 1 or 2, wherein: a means for storing the product-parts list of single-stage for each production unit stores linking information, the linking information designates the product-parts list of single-stage prepared by another production unit, wherein part in the list is stored as product in the list in the linked storing means.
 5. A system as set forth in claim 1 or claim 2, wherein: each of the lower level parts is displayed on the product-parts lists of multi-stages with its production unit.
 6. A system as set forth in claim 1 or claim 2, wherein: each of the parts is displayed on the product-parts lists of multi-stages with its logistics information from its production unit to the subsequent production unit.
 7. A system as set forth in claim 1 or claim 2, wherein: total lead time of a part from the lowest level part to the adjoining lower level part constituting the part and divided lead times into each part level are displayed separately.
 8. A system as set forth in claim 1 or claim 2, wherein: on the display of product-parts lists of multi-stages, at least one item selected out of the number of the parts required to produce a higher level part, the attribute of the part, and the number of types of the part, whereupon the cost of the part and the lead time of the part are displayed in a manner of comparison.
 9. A method for assisting findings of problems by revealing the problems existing and concealed in parts supplies chains, wherein parts produced in a production unit are supplied to and used in a subsequent production unit to produce higher level parts, the higher level parts produced in the subsequent production unit are supplied to and used in a further subsequent production unit to produce even higher level parts, and the sequences are repeatedly executed at multiple steps until final parts are produced in a final part production unit and the final parts are supplied to a final product production unit for producing final products, the method comprising: a step of preparing a product-parts list of single-stage at each of production units, a step of preparing linking information to a database prepared by a production unit of producing adjoining lower level part, a step of preparing parts supplies information corresponding to each of the lower level parts included in the product-parts list, this parts supplies information being at least one item selected out of the traveling distance of the part, the defect rate during the production of the part, the cost of the part, and the lead time of the part, and a step of storing reference values concerning to parts supplies information, a step for graphically displaying the product-parts list of multi-stages, parts supplies chains and the parts supplies information corresponding to each of the parts, wherein in the graphic display, the parts supplies information are displayed in a different mode depending on whether the reference values have been fulfilled or have not been fulfilled.
 10. A method for assisting findings of problems by revealing the problems existing and concealed in parts supplies chains, wherein parts produced in one production unit are supplied to and used in a subsequent production unit to produce higher level parts, the higher level parts produced in the subsequent production unit are supplied to and used in a further subsequent production unit to produce even higher level parts, and the sequences are repeatedly executed at multiple steps until final parts are produced in a final part production unit and the final parts are supplied to a final product production unit for producing final products, the method comprising: a step of preparing a product-parts list of single-stage at each of the production units, a step of preparing linking information to a database prepared by a production unit of producing adjoining lower level part, a step of preparing parts supplies information corresponding to each of the lower level parts included in the product-parts list, this parts supplies information being at least one item selected out of the traveling distance of the part, the defect rate during the production of the part, the cost of the part, and the lead time of the part, and a step of retrieving parts supplies information in accordance with retrieving criteria, a step for graphically displaying the product-parts list of multi-stages, parts supplies chains, and the parts supplies information corresponding to each of the parts, wherein in the graphic display, the parts and/or the parts supplies information corresponding to the parts supplies information retrieved are displayed in a different mode than the other.
 11. A program for assisting findings of problems revealing the problems existing and concealed in parts supplies chains, wherein parts produced in a production unit are supplied to and used in a subsequent production unit to produce higher level parts, the higher level parts produced in the subsequent production unit are supplied to and used in a further subsequent production unit to produce even higher level parts, and the sequences are repeatedly executed at multiple steps until final parts are produced in a final part production unit and the final parts are supplied to a final product production unit for producing final products, the program operates a computer to execute the steps comprising: a step of obtaining data from a database prepared by each of the production units, the database including a product-parts list of single-stage at each of the production units, a linking information to a database prepared by a production unit of producing adjoining lower level part, and parts supplies information corresponding to each of the lower level parts included in the product-parts list, the parts supplies information being at least one item selected out of the traveling distance of the part, the defect rate during the production of the part, the cost of the part, and the lead time of the part, and a step of storing reference vales concerning to parts supplies information, a step of graphically displaying the product-parts list of multi-stages, parts supplies chains, and the parts supplies information corresponding to each of the parts, wherein in the graphic display, the parts supplies information are displayed in a different mode depending on whether the reference values have been fulfilled or have not been fulfilled.
 12. A program for assisting findings of problems by revealing the problems existing and concealed in parts supplies chains, wherein parts produced in a production unit are supplied to and used in a subsequent production unit to produce higher level parts, the higher level parts produced in the subsequent production unit are supplied to and used in a further subsequent production unit to produce even higher level parts, and the sequences are repeatedly executed at multiple steps until final parts are produced in a final part production unit and the final parts are supplied to a final product production unit for producing final products, the program operates a computer to execute the steps comprising: a step of obtaining data from a database prepared by each of production units, the database including a product-parts list of single-stage at each of production units, a linking information to a database prepared by a production unit of producing adjoining lower level part, and parts supplies information corresponding to each of the lower level parts included in the product-parts list, the parts supplies information being at least one item selected out of the traveling distance of the part, the defect rate during the production of the part, the cost of the part, and the lead time of the part, and a step of retrieving parts supplies information in accordance with retrieving criteria, a step of graphically displaying the product-parts list of multi-stages, parts supplies chains and the parts supplies information corresponding to each of the parts, wherein in the graphic display, the parts/and/or the parts supplies information corresponding to the parts supply information retrieved are displayed in a different mode than the other. 